Sierra Sports Master 9mm Caliber 90 Grain JHP Rifle Bullets. 355 inch diameter. Be sure that the handgun cartridge for which you are loading uses .355 inch diameter bullets. The 90 grain #8100 was originally introduced in the hollow cavity (JHC) design in 1970 but the design was changed in 1983 to the current hollow point (JHP) to enhance feeding in semi-auto pistols. Sierra s Power Jacket with skives enhances expansion in varmints at handgun velocities. Pure lead is used for the core to give good penetration with excellent expansion. The 90 grain #8100 is an excellent bullet for the 380 ACP and can be loaded in that cartridge to excellent velocities for high energy release and effective self defense. Specifications for Sierra Bullets Sports Master Pistol Bullets 9mm 90 Grain Jacketed Hollow Point: Manufacturer: Sierra Bullets Gun Type: Pistol Bullet Type: Jacketed Hollow Point (JHP) Hollow Point (HP) Caliber: 9mm Luger Bullet Weight: 90 grain Sectional Density: 0.102 Projectile Caliber: .355 Caliber Country of Origin: USA Fabric/Material: Copper Features of Sierra Bullets Sports Master Pistol Bullets 9mm 90 Grain Jacketed Hollow Point SportsMaster Bullets are handgun bullets designed for hunting or personal defense built for reliable expansion. Package Contents: Sierra Bullets Sports Master Pistol Bullets 9mm 90 Grain Jacketed Hollow Point Sierra 8100 Sports Master 9mm .355 90 GR Jacketed Hollow Point JHP 100 Box